Technical Field
The disclosed embodiments relate to the field of wireless communications, including communicating resource units allocations in wireless communications.
Background
Generally, frames transmitted by an Institute of Electrical and Electronics Engineers (IEEE) 802.11 device have a significant amount of overhead, including radio level headers, Media Access Control (MAC) headers, interframe spacing, and acknowledgment of transmitted frames. At higher traffic conditions, this overhead can consume more bandwidth than payload of data frames.
To address this issue, the 802.11ax standard defines a broadcast trigger frame. The broadcast trigger frame is transmitted separately from and prior to data transmissions. The broadcast trigger frame enables a random access mechanism for an OFDMA transmission by multiple stations in a wireless local area network (WLAN). An access point (AP) can broadcast the trigger frame to one or more stations. After broadcasting the trigger frame, the AP transmits a downlink (DL) data transmission in accordance with the parameters specified by the trigger frame. The AP can subsequently receive uplink (UL) data transmissions, such as acknowledgement (ACK) messages or block acknowledgment (BA) messages, transmitted by one or more stations in accordance with the trigger frame parameters.
However, broadcasting the trigger frame prior to the data transmissions can add significant overhead to transmit operations. In some circumstances, the benefits gained from employing the broadcast trigger frame are outweighed by the complexity involved in computing trigger frame parameters, the amount of extra transmissions used in sending the trigger frames, and/or the time required to send this extra overhead information.